This invention relates broadly to catheters and more specifically to catheters having a plurality of separated lumens, especially blood vessel catheters.
Quite often, treatment of medical patients requires simultaneous infusion, and/or withdrawal of various fluids from patients' blood streams. Many patients, especially those under intensive care, require simultaneous drug administration, IV feedings, CVP monitoring, and periodic blood sampling. Basically, the rotor 34 is a movable, adjusting device which is used for reducing the number of active input tubes 58, 60, and 62 transmitting fluid in while simultaneously changing connections to the output tubes 76, 78 and 80 so that all of the output tubes continue to transmit fluid out without substantially mixing them. In the past, this has meant that such patients have required insertion of a corresponding number of catheter devices simultaneously coupled to major blood vessels. The implantation of a plurality of catheters involves an undue amount of work for medical personnel and is a source of great discomfort to patients. In addition, the administration of multiple catheters increases the risk of vascular trauma, bleeding, and infection by providing additional passages for infection-causing bacteria.
To overcome these difficulties it has been suggested to employ a single venous catheter device having multiple lumens therein (U.S. Pat. No. Re.31,873 to Howes). Howes points out in this patent that fluids applied through the various lumens of his venous catheter device are often incompatible with one another and for this reason Howe provides that each lumen of his venous catheter has a distal terminus, or outlet opening, spaced along the catheter from the distal termini of the other lumens. Howes points out that such an arrangement allows his plural-lumen venous catheter device to be usable for infusion of more than one fluid simultaneously into a vein of a patient as well as to be used for making withdrawals for CVP measurements. Although the device described in Howes has a number of advantages over separate catheters, it also has some disadvantages. A primary disadvantage of the multiple-lumen venous catheter device described in Howes results from the fact that intravenous treatment of patients varies tremendously over a recovery period. That is, when a patient is first placed under intensive care, he often requires the administration of intravenous fluids and/or medications of various types in each of the catheter's lumens. However, as the patient recovers, some of these fluid transfers can be discontinued while others must be continued. For example, it may become desirable to discontinue one drug infusion while continuing others. When patients are treated with separate catheters, discontinuance of one type of intravenous treatment is not a problem because the catheter used for the discontinued treatment is simply resealed or removed. However, when a multi-lumen venous catheter device, such as is described in U.S. Pat. No. Re 31, 873 to Howes, is used, the lumen for the discontinued fluid transfer cannot be removed because other lumens of the multi-lumen catheter are still being used. When use of one lumen of a multi-lumen catheter is discontinued, blood backs up in the lumen and blood clots are usually deposited therein which ultimately occludes the lumen preventing its further use. Additionally, bacteria gets in these blood clots and causes infection which can then spread throughout the patient's body causing sepsis and death. In order to avoid this, when a multi-lumen catheter is used, with one of the lumens not being used, this not-used lumen must be periodically flushed, with many hospitals dictating that nurses must flush unused lumens during every shift. Further, many hospitals dictate that multi-lumen catheters having unused lumens must be changed more frequently than catheters in which all lumens are used. These procedures are not only very expensive and labor intensive, but also increase risks to patients by additional instrumentation increasing the probability of vascular trauma, bleeding, and infection. Also, in carrying out these procedures, patients are brought under increased discomfort and stress.
Thus, it is an object of this invention to provide a multi-lumen-catheter flow valve system which continuously and automatically flushes every lumen of a multi-lumen catheter, from even a single input lumen, so that the remaining lumens do not have to be specially flushed. This will reduce the incidence of occlusion and infection so that the catheter need not be changed substantially more frequently than are single-lumen blood catheters.
It is also an object of this invention to provide a multi-lumen-catheter flow valve system which is not unduly complicated and which can be relatively inexpensively manufactured.